SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492016-12-09T10:25:37-07:00SparkFun Electronicst-storm on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)t-stormurn:uuid:eddcb4a3-9756-fdf9-61e5-fb1130e4f0ad2015-02-25T10:09:23-07:00<p>Hello, I was playing around with my Redbot and found this same issue. I thought I could change the library file and fix it but it didn&rsquo;t change anything.
Were you able to find a solution to this?
Thanks</p>Customer #368578 on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)Customer #368578urn:uuid:3089c3ad-9d18-4f23-b42c-e368436d7db92014-06-16T06:35:20-06:00<p>the breakout uses the MMA8452Q, right?
MMA8462Q is a typo, the link goes to the datasheet for the MMA8452Q</p>Customer #471855 on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)Customer #471855urn:uuid:90307b5d-d28f-d20f-4fc8-13da08c2bd012014-01-27T21:41:44-07:00<p>I don&rsquo;t want to spam but I cross posted this comment in the MMA8452Q Breakout Board section also.</p>
<p>I was able to modify the RedBot accelerometer (MMA8462Q) CPP file to add two&rsquo;s complement checking and LSB shifting ala the advanced example in the Example Code (see MMA8452Q Breakout Board). Everything works as expected EXCEPT the g values are four times too large. I checked and double checked that the scale setting is +/- 8 g, I&rsquo;m in the low res mode, the logic looks fine, and I&rsquo;m dividing the count by 256 for the 8 g scale and I am getting ~+4.00 g in the z-direction, not ~+1.00 g as I expect. I&rsquo;m using 8 for the scale factor in constructing the divisor for the counts (1/(1&lt;&lt;12)/(2*SCALE)) = 1/256 for 8 g full scale, yet I am getting an extra factor of four. I checked the raw output of the concatenated z-bytes which was ~16000 unshifted = 14-bits! What gives???</p>
<p>Thanks for any suggestions (other than dividing by four which I am currently doing)!</p>ebird97 on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)ebird97urn:uuid:1e9b4b00-cbd6-2648-e86f-c3eb70a528f52013-11-30T00:19:09-07:00<p>It doesn&rsquo;t &ldquo;use up&rdquo; the I2C pins, those pins are able to connect to over 120 devices using the same two lines.</p>Customer #394180 on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)Customer #394180urn:uuid:92c05a7a-6d12-ceab-ff02-1d91ef3a0f1f2013-10-24T06:25:44-06:00<p>You&rsquo;re wanting something stupid.</p>
<p>Don&rsquo;t know why you wanted to hear that , but always willing to make a fellow hacker happy :-)</p>
<p>Seriously, though, there&rsquo;s nothing wrong with soldering and anyone who wants to hack robots ought to be comfortable with the level of soldering in this kit. Honestly, I think at this point we should all be proficient in SMD soldering, not just thru-hole.</p>
<p>As far as the example software goes, it&rsquo;s just that, example software. You are perfectly free to write your own using any library that you&rsquo;d like. The problem with tying examples to a specific library is that libraries come and go, or they change. Examples need to be universal so they can be more easily ported between varying platforms. If there is a working example with definitions that you don&rsquo;t like, it should be just a matter of some text editing to change it over.</p>
<p>Won&rsquo;t comment on the physical interface issue that you raised since I haven&rsquo;t had time to look at that.</p>
<p>Good luck with your robot</p>Customer #260321 on SEN-11770 - SparkFun RedBot Sensor - Accelerometer (Sale)Customer #260321urn:uuid:74cc2ce6-cac6-365f-dd06-b6cbe2d4a9772013-08-23T18:37:41-06:00<p>I am looking at the RedBot as an entry-level complete robot kit, and the little red magnetic screwdriver is a nice touch. However, when I got to the Accelerometer I found some unplesant features. (1) soldering to to mainboard is required, unless I buy some female breakout headers and solder them. (2) This accelerometer (and its example software) uses up the SCA/SCL (I2C) pins without allowing additional I2C devices, and the example software doesn&rsquo;t even use wire.h to access them. I&rsquo;d much prefer a 1x4-pin daisy-chained physical interface. Please tell me I&rsquo;m wanting something stupid.</p>